It took a decade of effort, heart-breaking disappointments, and the largest ship afloat before Cyrus Field could lay a successful cable across the Atlantic

The eastward-sailing Agamemnon , on the other hand, had once again had an adventurous voyage, and several times had skirted mechanical or electrical disaster. Considering the conditions under which Thomson and his assistants worked, it is astonishing that they were able to keep their instruments operating at all. Listen to this description of the telegraph room as given by the Sydney Morning Herald: The electrical room is on the starboard side of the main deck forward. The arrangements have been altered several times in order to avoid the water which showers down from the upper deck. At one end of the little place the batteries are ranged on shelves and railed in.… The most valuable observation is taken in sending on the marine galvanometer. Three seconds before it is taken, the clerk who times all the observations by a watch regulated by a chronometer too valuable to be brought into so wet a place says, “Look out.” The other clerk at once fixes his eye on the spot of light, and immediately the word is given “Now” records the indication. This testing is made from minute to minute, so that a flaw is detected the moment it occurs.

The ships had spliced the cable on July 29, 1858, midway between Europe and America, in water 1,500 fathoms deep. To let the Times continue the story: For the first three hours the ships proceeded very slowly, paying out a great quantity of slack, but after the expiration of this time, the speed of the Agamemnon was increased to about five knots, the cable going at about six.… Shortly after 6 o’clock a very large whale was seen approaching the starboard bow at a great speed, rolling and tossing the sea into foam all around.…It appeared as if it were making direct for the cable, and great was the relief of all when the ponderous living mass was seen slowly to pass astern, just grazing the cable where it entered the water.…

A few hours later there was a real crisis, vividly depicted by the Sydney Morning Herald ’s reporter:
We had signalled the Niagara “40 miles submerged” and she was just beginning her acknowledgement when suddenly, at 10 p.m., communication ceased. According to orders, those on duty sent at once for Dr. Thomson. He came in a fearful state of excitement. The very thought of disaster seemed to overpower him. His hand shook so much that he could scarcely adjust his eyeglass. The veins on his forehead were swollen. His face was deathly pale. After consulting his marine galvanometer, he said the conducting wire was broken, but still insulated from the water.… There did not seem to be any room for hope; but still it was determined to keep the cable going out, that all opportunity might be given for resuscitation. The scene in and about the electrical room was such as I shall never forget. The two clerks on duty, watching with the common anxiety depicted on their faces, for a propitious signal; Dr. Thomson, in a perfect fever of nervous excitement, shaking like an aspen leaf, yet in mind keen and collected, testing and waiting.… Mr. Bright, standing like a boy caught in a fault, his lips and cheeks smeared with tar, biting his nails and looking to the Professor for advice.… The eyes of all were directed on the instruments, watching for the slightest quiver indicative of life. Such a scene was never witnessed save by the bedside of the dying.… Dr. Thomson and the others left the room, convinced that they were once more doomed to disappointment.…

But they were not. No one ever knew exactly what had happened; perhaps the cable’s conducting core had broken under the strain of laying, but reunited on the sea bed when the tension was relaxed, and the elasticity of the coverings brought the wires together again. In any event, the signals returned at last, and the cable spoke again.

Our joy was so deep and earnest that it did not suffer us to speak for some seconds. But when the first stun of surprise and pleasure passed, each one began trying to express his feelings in some way more or less energetic. Dr. Thomson laughed right loud and heartily. Never was more anxiety compressed into such a space. It lasted exactly one hour and a half, but it did not seem to us a third of that time.…

The ship now began to run into heavy seas and started to pitch and roll in a manner that put a great strain on the cable.

During Sunday the sea and wind increased, and before the evening it blew a smart gale. Now indeed were the energy and activity of all engaged in the operation tasked to the utmost … the engineers durst not let their attention be removed from their occupation for one moment, for on their releasing the brake on the paying-out gear every time the stern of the ship fell into the trough of the sea entirely depended the safety of the cable.… Throughout the night, there were few who had the least expectation of the cable holding on till morning, and many remained awake listening for the sound that all most dreaded to hear—namely, the gun which should announce the failure of all our hopes. But still the cable, which, in comparison with the ship from which it was paid out, and the gigantic waves among which it was delivered, was but a mere thread, continued to hold on, only leaving a silvery phosphorus line upon the stupendous seas as they rolled on towards the ship.…